Recently, techniques for building various kinds of user service circumstances using the Internet have been serviced with the development of communication and network technologies.
A location inquiry technique provides services for inquiring about location information of a user and other users, in which a user's own location information or the counterpart's location information can be inquired using a mobile communication terminal not only in wired Internet circumstances but also in wireless internet environment. That is, a user's own location information or the like can be inquired, and another user's location information can be retrieved and identified in the wired and wireless Internet environment.
Especially, “a location-based alert service” is a service in which, if a previously specified counterpart moves forward or away from a user, a corresponding movement is informed through short message or the like.
FIG. 1 is a block diagram showing a configuration of a conventional location-based service system.
A conventional system for providing conventional location-based service includes a mobile client group 101 having a plurality of mobile clients, a client group 102 having a plurality of clients, a base station 103, a mobile switching center 104, a location processing server 105, a map server 106, a map DB 107, an SMS server 108, the Internet 109, a web server 110, a location service server 111 and a location inquiry mutual authentication DB 112.
Each of the mobile clients in the mobile client group 101 is a mobile communication means, i.e., a wireless portable terminal (e.g., a cellular phone, a PCS, a PDA, an IMT-2000 or the like), which is connectable to the Internet 109 through a mobile switching center 104 or the like. Each of the mobile clients may be connected to the location service server 111 through the Internet 109 and the web server 110 to receive location based services provided using the Internet 109. Further, the mobile client may be linked with the location service server 111 through the base station 103, the mobile switching center 104 or the like to use location information services with the wireless portable terminal through the SMS server 108.
Each of the clients in the client group 102 is a system connectable to the Internet 109 using a modem, e.g., an dedicated line, an ADSL or the like. Like each of the mobile clients in the mobile client group 101, each of the clients may be connected to the location service server 111 through the Internet 109 and the web server 110 in order to receive location based services provided using the Internet 109.
The base station 103 provides communication services between a mobile client within its own coverage (i.e., a cell) and the mobile switching center 104. The mobile switching center 104 includes base station controllers which oversee a plurality of base stations, a WAP gateway, a Home Location Register (HLR), a Visitor Location Register (VLR) and the like. The mobile switching center 104 provides various communication services performed between each of the mobile clients within the coverage of each base station which is under the control of the mobile switching center 104 and a counterpart (or a mobile client), manages a local registration state of the mobile clients within the coverage of each base station which is under the control of the mobile switching center 104, and connects itself to the Internet 109 through the WAP gateway to provide location information services to each of the mobile clients.
Further, when there is a location detection request for a specific mobile client (i.e., a client that is a location information object of the location inquiry services) from the location processing server 105 in the mobile switching center 104, it refers to the Home Location Register (HLR) and the Visitor Location Register (VLR) and searches a base station which currently covers and serves the mobile client of interest. If a base station within which the corresponding mobile client exists is founded, the mobile switching center 104 provides the location value of the corresponding base station for the location processing server 105. Furthermore, if the specific mobile client, which is an object of which location is inquired, is a terminal having a GPS module therein, the mobile client receives location information from a GPS satellites to provide the location value of the calculated result of the location information for the location processing server 105.
The web server 110 provides location information services to each of the clients or each of the mobile clients. When a client or a mobile client connect itself to the Internet 109 to request the location information services, the web server 110 links between the corresponding client (or the mobile client) and the location service server 111 to provide the location information services corresponding thereto through various kinds of menu screens (e.g., an initial menu screen, a location information menu screen and the like).
Further, the location service server 111 registers and manages information related virtually to location information services put in or selected by a user, such as a location, a location permission or the like, which is requested by each of the users (i.e., the client or the mobile client). The location service server 111 stores/registers the result of mutual authentication for the location information services in the location inquiry mutual authentication DB 112 to manage it.
If address and/or mutual information are entered together with a location data request signal from the location service server 111 when the location based services are provided, the map server 106 searches the map DB 107 in which electronic map data is built and stored in order to detect a location value (i.e., a coordinate value) for a requested address and/or mutual information on an electronic map, and to transmit the detected coordinate value as location data to the location service server 111. If the location value (i.e., the coordination value) is input together with the map data request signal from the location service server 111 when the location based services are provided, the map server 106 fetches a map data corresponding to the received location value from the map DB 107 to transmit it to the location service server 111.
Further, if a mobile client selects its own current location as a registration location when the location information service is provided, the map server 106 transmits identification information on the corresponding mobile client together with a location data request signal, e.g. identification information on the corresponding mobile client together with a corresponding location search request signal, from the location service server 111. If the location value (i.e., the longitude and latitude coordinate values) of a base station in which the corresponding mobile client is served is provided from the location service server 111 through the location processing server 105 in response to the identification information on the corresponding mobile client, the map server 106 searches and reads coordinate value corresponding to the location value of the corresponding base station from the map DB 107 so as to transmit it to the location service server 111.
A method generally considered to provide a conventional location-based alert service is to periodically inquire the location of a mobile communication terminal. For example, assuming that a location inquiry of the mobile communication terminal is performed every 10 minutes, location inquiries are performed 144(=60/10*24) times in 24 hours. If the number of object mobile communication terminals on which location inquiries should be performed is a million, total location inquiries are performed 144 million(=144*one million) times in 24 hours. There is a disadvantage in that such enormous volume of the location inquiries in 24 hours causes a considerable load to a mobile communication network and, as a result, exacts unnecessary excessive costs for performing a location-based alert service.